Bone grafting performed by orthopedic surgeons to repair bone fractures can be largely classified into autograft, allograft and artificial bone graft. Among them, autograft shows excellent biocompatibility, but it is disadvantageous in that the size of bone is limited and the bone has to be harvested from the patient's own body. Allograft is associated with the problem that the bone is often obtained from a cadaver of an unknown source. Also, the donated bone may cause infections. Thus, development of an artificial bone capable of replacing the natural bone is strongly required. However, there remain problems with regard to improvement in biocompatibility with the human body and mechanical strength.
The natural bone exhibits better strength than any other synthetic materials developed for artificial bone thus far. This may be due to the characteristic lamellar microstructure of the natural bone. The most important factor in developing artificial bone is to provide superior mechanical property as well as biocompatibility.
Although many researchers are striving to mimic the natural bone using bioceramics, an artificial bone satisfying both biocompatibility and mechanical strength is not developed as yet.